FISHERY INDUSTRIES OF THE UNITED STATES, 1934 91 



prepared according to various experimental methods of manufacture 

 by teclmolopsts in our Seattle and Alaska laboratories. In g:eneral, 

 oils prci)arod from salmon livers arc approximately 5 to 20 times as 

 potent in vitamin A and ap])roximately 2 to 3 times as i)otent in 

 vitamin D as an averaice medicinal cod-liver oil. The oils prepared 

 from salmon egi:;s and from trimmings compare favorably in vitamin 

 potency with an average medicinal cod-liver oil. The results obtained 

 in 1934 averaged about the same vitandn potency as the samples pre- 

 pared experimentally in 1933 insofar as their vitamin D content was 

 concerned, although some of them were somewhat low in vitamin A 

 potency. 



A more detailed discussion of the variation in potencies of salmon 

 oils appears in a previous section of this report under the heading of 

 "Utilization of salmon cannery waste." 



HORSE MACKEREL-LIVER OIL 



During the past year, a sample of oil extracted by ethylene dichlo- 

 ride from the liver of the horse mackerel or Atlantic tuna was tested 

 for vitamins A and D. As a result, it was found that this oil con- 

 tained 7,100 international vitamin D units and 60,000 international 

 vitamin A units. 



CRAB MEAT 



Samples of fresh crab meat as prepared commercially from the blue 

 crab of Chesapeake Bay were tested for vitamins A and G. In the 

 vitamin A tests, the crab meat was found to contain 40 to 55 U. S. P. 

 vitamun A units per ounce of crab meat. In the vitamin G tests, the 

 crab meat was found to contain about one-half a unit of vitamin G 

 per gram of crab meat. The so-called "curative technique" was used 

 for the vitamin A assay, while the "Sherm.an" method was used for 

 the vitamin G assay. 



SODIUM ALGINATE 



Because, in recent years, sodium alginate, a product made from the 

 Pacific coast kelp, has found widespread use in dairy products as a 

 stabilizer, the Bureau was requested by the industry to determine its 

 food value. Accordingly, tests were made of this product with lal)ora- 

 tory animals. Fed at the level of 3 percent of the ration, sodium 

 alginate showed definite food value. Our tests indicated that this 

 product possesses the same general properties in stimilating growth 

 and appetite in the experimental animals (white rats) as was found in 

 the kelp-meal tests conducted by our technologists, a few years ago 

 (Technological Report No. 5). 



CONCH MEAT 



Considerable quantities of conchs are found along the coast of 

 Florida and in certain of our possessions in the West Indies. The 

 meat of this animal is highly prized for food in different localities and 

 in recent years an effort has been made to widen distribution. This 

 has been done by dev^eloping a canning industry in Florida which 

 produces such products from conch meat as cocktails, juices, concen- 

 trates, etc. Sinre no analyses of conch meat were available, a study 



